The present invention pertains to a multiftnctional optical switch that can be employed inter alia as an optical wavelength division multiplexer, optical wavelength division demultiplexer, optical add-drop multiplexer and/or optical inter-connect device. The invention further provides novel methods of manufacturing the optical switch. The optical switch can comprise a single layer, and optimally includes a plurality of layers which each comprise an optical nonlinear second-order polymer. The optical nonlinear second-order polymer present in each layer preferably differs from that present in any other layer in terms of its absorption maximum (i.e., due to possession of different chromophores).
The new century heralds an unprecedented demand for ability to transport and process large amounts of information. The incredible growth in demand for Internet resources and the constraints of bandwidth are but just two of the factors that compel the telecommunications industry to pursue less expensive and more efficient options in the form of xe2x80x9call-opticalxe2x80x9d networks (as well as networks that may not solely comprise, but do include, optical components).
For industries to meet such demand, further development and improvement of optoelectronic components (currently bulky and expensive) is necessary. In particular, it will be necessary to: (i) reduce the size of the optical components; (ii) increase the number of channels on a given optical fiber; and (iii) simplify the fabrication process to reduce costs. In addition, higher and higher transmission bit-rates of data are needed to expand the capability of current fiber communication channels.
Wavelength division multiplexers (WDMs) have become one of the hottest commodity items in lightwave applications today since they allow multiple wavelengths to be used as channels to transmit data within a single optical fiber. WDMs traditionally are based on inorganic materials. However, organic materials, namely polymeric materials, have recently reached a performance maturity to compete with these inorganic optical materials. Such materials exhibit physical and chemical xe2x80x9cflexibilityxe2x80x9d, and, for instance, can be relatively easily chemically modified to suit specific applications. This flexibility of polymeric materials makes possible, among other things, rapid cycles of material design, preparation, testing, and redesign. Organic polymeric materials are readily fabricated into integrated optical circuitry, which contributes to lower costs of manufacture. Polymer-based devices could ultimately be mass-produced using simple printing processes. Moreover, organic polymers provide a large inventory of photonic materials that can have a low dielectric constant. Certain of the polymers show high stability and optical nonlinearity.
In the 1990s, polymer-based interferometers and other polymer-based devices generated great interest (Girton et al. xe2x80x9cElectrooptic Polymer Mach-Zehnder Modulator.xe2x80x9d In ACS Symposium Series 601, Polymers for Second-Order Nonlinear Optics (Washington D.C. 1995), 456-468). Polymeric materials have recently emerged as materials for use in optical applications (Keil, xe2x80x9cRealization of IO-Polymer-Components and present State in Polymer Technologyxe2x80x9d In Integrated Optics and Micro-Optics With Polymers, (Stuttgart-Leipzig: B. G. Teubner Verlagsgesellscaft, 1993), 273; Ito et al., eds., Polymeric Materials for Microelectronics Applications, ACS Symposium Series 579 (Washington, D.C.: American Chemical Society, 1991); Lindsay et al., eds., Polymers for Second Order Nonlinear Optics, ACS Symposium Series 601 (Wash., D.C.: American Chemical Society, 1995), pp. 1, 111, 130, 158, 172, 374, 381; Edelman et al., eds.
Among the more recently developed polymeric materials are polyimides that have been shown to have superior optical and physical characteristics. In particular, certain polyimides show thermal stability, as well as high optical nonlinearity (as reflected in their r33 values) (Lindsay et al., supra). The company Akzo Nobel uses polymers to make optical switches. Similarly, the company Lightwave has combined optical design with a polymer-materials technology and semiconductor techniques to make waveguide structures directly on a wafer where the silicon acts as a platform only. Lightwave uses a polyimide polymer having a low dielectric constant and high temperature stability. The material made by Lightwave acts as an optical pipe, but it also can be made optically active by applying a voltage across the material to change the index of refraction. Then the light can be modulated or switched from one path to another, or just modulated at very high speeds. Despite these advances, considerable advances in the optics field still need to be made to meet the recent demands of the telecommunications industry. For instance, devices constructed to date are single-layer devices, and/or are planar (i.e., the switching occurs in one plane to adjacent waveguides).
Thus, the present invention provides a novel device, i.e., an optical switch, that can perform several critical tasks for the telecommunications industryxe2x80x94e.g., wavelength division multiplexing, wavelength division demultiplexing, performance as an add/drop filter and/or interconnect device. The devices according to the invention conceivably can be manufactured at substantially less than the cost of the silicon-based devices due to novel means for their production, as further described herein. These and other objects and advantages of the present invention, as well as additional inventive features, will be apparent from the following description of the invention provided herein.
The present invention pertains to a multifunctional optical switch, and novel methods for its manufacture. The optical switch can comprise a single layer, and optimally comprises a plurality of layers (i.e., at least two layers, preferably which are stacked), which desirably each comprise an optical nonlinear second-order polymer. The optical nonlinear second-order polymer present in each layer preferably differs from that present in any other layer in terms of its light absorption maximum. The optical switch according to the invention desirably can be employed as an optical wavelength division multiplexer, wavelength division demultiplexer, add-drop multiplexer and/or inter-connect device, among other things. Other uses and devices of the optical switch of the invention would be apparent to one skilled in the art.